<?php // $Id: subscribe.php,v 1.37.2.7 2008/04/13 19:10:35 skodak Exp $

//  Subscribe to or unsubscribe from a forum.

	require_once("../../config.php");
	require_once("lib.php");

	$id = required_param('id',PARAM_INT);	  // The forum to subscribe or unsubscribe to
	$force = optional_param('force','',PARAM_ALPHA);  // Force everyone to be subscribed to this forum?
	$user = optional_param('user',0,PARAM_INT);

	if (! $forum = get_record("forum", "id", $id)) {
		error("Forum ID was incorrect");
	}

	if (! $course = get_record("course", "id", $forum->course)) {
		error("Forum doesn't belong to a course!");
	}

	if ($cm = get_coursemodule_from_instance("forum", $forum->id, $course->id)) {
		$context = get_context_instance(CONTEXT_MODULE, $cm->id);
	} else {
		$cm->id = 0;
		$context = get_context_instance(CONTEXT_MODULE, $cm->id);
	}

	if ($user) {
		if (!has_capability('mod/forum:managesubscriptions', $context)) {
			error('You do not have the permission to subscribe/unsubscribe other people!');
		}
		if (!$user = get_record("user", "id", $user)) {
			error("User ID was incorrect");
		}
	} else {
		$user = $USER;
	}

	if (groupmode($course, $cm)
				and !forum_is_subscribed($user->id, $forum)
				and !has_capability('moodle/site:accessallgroups', $context)) {
		if (!mygroupid($course->id)) {
			error('Sorry, but you must be a group member to subscribe.');
		}
	}

	require_login($course->id, false, $cm);

	if (isguest()) {   // Guests can't subscribe
		$wwwroot = $CFG->wwwroot.'/login/index.php';
		if (!empty($CFG->loginhttps)) {
			$wwwroot = str_replace('http:','https:', $wwwroot);
		}
		
		$navigation = build_navigation('', $cm);
		print_header($course->shortname, $course->fullname, $navigation, '', '', true, "", navmenu($course, $cm));
		
		notice_yesno(get_string('noguestsubscribe', 'forum').'<br /><br />'.get_string('liketologin'),
					 $wwwroot, $_SERVER['HTTP_REFERER']);
		print_footer($course);
		exit;
	}

	$returnto = optional_param('backtoindex',0,PARAM_INT) 
		? "index.php?id=".$course->id 
		: "view.php?f=$id";

	if ($force and has_capability('mod/forum:managesubscriptions', $context)) {
		if (forum_is_forcesubscribed($forum)) {
			forum_forcesubscribe($forum->id, 0);
			redirect($returnto, get_string("everyonecannowchoose", "forum"), 1);
		} else {
			forum_forcesubscribe($forum->id, 1);
			redirect($returnto, get_string("everyoneisnowsubscribed", "forum"), 1);
		}
	}

	if (forum_is_forcesubscribed($forum)) {
		redirect($returnto, get_string("everyoneisnowsubscribed", "forum"), 1);
	}

	$info->name  = fullname($user);
	$info->forum = format_string($forum->name);

	if (forum_is_subscribed($user->id, $forum->id)) {
		if (forum_unsubscribe($user->id, $forum->id)) {
			add_to_log($course->id, "forum", "unsubscribe", "view.php?f=$forum->id", $forum->id, $cm->id);
			redirect($returnto, get_string("nownotsubscribed", "forum", $info), 1);
		} else {
			error("Could not unsubscribe you from that forum", $_SERVER["HTTP_REFERER"]);
		}

	} else {  // subscribe
		if ($forum->forcesubscribe == FORUM_DISALLOWSUBSCRIBE &&
					!has_capability('mod/forum:managesubscriptions', $context)) {
			print_error('disallowsubscribe', 'forum', $_SERVER["HTTP_REFERER"]);
		}
		if (!has_capability('mod/forum:viewdiscussion', $context)) {
			error("Could not subscribe you to that forum", $_SERVER["HTTP_REFERER"]);
		}
		if (forum_subscribe($user->id, $forum->id) ) {
			add_to_log($course->id, "forum", "subscribe", "view.php?f=$forum->id", $forum->id, $cm->id);
			redirect($returnto, get_string("nowsubscribed", "forum", $info), 1);
		} else {
			error("Could not subscribe you to that forum", $_SERVER["HTTP_REFERER"]);
		}
	}

?>
